1. Field of the Invention
This invention relates to a method of integratively managing, in an apparatus which transmits and receives ATM cells making use of an asynchronous transfer mode (hereinafter referred to as xe2x80x9cATMxe2x80x9d) network, MIBs (Management Information Bases) provided in a plurality of servers for ATM communication.
2. Description of the Related Art
A conventional management method has the following problems.
The first problem is that, in environment wherein various ATM communication server modules are incorporated in the same ATM switch apparatus, if the ATM switch body performs Simple Network Management Protocol (SNMP) communication with all of the server modules, then a high load is applied to processing of a CPU of the ATM switch body, which has a bad influence upon the other processing than the SNMP.
The second problem is that, in environment wherein various ATM communication server modules are incorporated in the same ATM switch apparatus, if local processor communication is use for SNMP communication between a CPU of the ATM switch body and CPUs of servers, then the load of the traffic applied to the local processor communication increases, which has a bad influence on communication which is more significant than the SNMP communication, for example, on communication for incorporation state management or apparatus failure management.
The third problem is that, even if it is assumed that the second problem described above is solved and SNMP communication is performed by virtual connection (hereinafter referred to as xe2x80x9cVCxe2x80x9d) communication, if all VCs are made permanent virtual connections (hereinafter referred to as xe2x80x9cPVCsxe2x80x9d), then normally necessary VC resources are consumed and the VC resources are uselessly consumed much.
The fourth problem is that the conventional management method is a closely coupled system wherein, since an SNMP interface is incorporated in an ATM switch and MIB get interface is incorporated in each server module, each time addition/modification to an application MIB of a server module is performed, addition/modification also to the SNMP interface of the ATM switch is required.
Another method is disclosed in Japanese Patent Laid-Open No. Hei 7-226777 and Japanese Patent Laid-Open No. Hei 7-319793 wherein, as a method of managing a network hierarchically, an integrative manager, a sub manager and an agent are arranged discretely as separate apparatus on a network and communication between the managers and the agent is performed with the SNMP. While the method uses the SNMP, SNMP communication is performed between external apparatus through the network.
It is an object of the present invention to lower, when, where a plurality of servers are incorporated in an ATM switch apparatus, a network management system accesses a management information base of any of the servers of the ATM switch in accordance with an SNMP procedure, the load applied to CPU processing of the ATM switch body to minimize the influence to be had upon the processing capacity for the other functions than the SNMP function.
In order to attain the object described above, according to the present invention, there is provided an management information base integrative management method for an asynchronous transfer mode server for accessing, from a network management system through an asynchronous transfer mode switch apparatus in which a plurality of servers are incorporated, a management information base of any of the servers in accordance with a simple network management protocol procedure, comprising the steps of setting one of the plurality of servers as a master server and setting the other ones of the plurality of servers as slave servers, accessing, from the asynchronous transfer mode switch, the master server representatively in accordance with the simple network management protocol procedure, and accessing, from the master server, any of the slave servers over a virtual connection.
The simple network management protocol communication between the asynchronous transfer mode switch and the master server may be performed over a virtual connection. In this instance, preferably a permanent virtual connection is used for the communication between the asynchronous transfer mode switch and the master server, and a switched virtual connection is used for the communication between the master server and any of the slave servers. Further, upon setup over the switched virtual connection between the master server and any of the slave servers, the slave server may start up a timer thereof and retry the setup at a set time of the timer.
Preferably, the master server uses index information for management of the slave servers, and index updating notification/response are performed between the master and slave servers. In this instance, in an index collection phase, timeout supervision of a response may be performed upon index updating from any of the slave servers to the master server. Further, when timeout of the index updating response occurs, preferably re-sending processing of the index updating notification is performed.
Preferably, when the asynchronous transfer mode switch body communicates with the master server in an simple network management protocol operation phase, the asynchronous transfer mode switch body communicates in a unit of an management information base group using a Get/Set common function. In this instance, timeout supervision of the Get/Set response may be performed between the asynchronous transfer mode switch and the master server and between the master server and any of the slave servers in the simple network management protocol operation phase.
Preferably, when the master server suffers from a failure, the asynchronous transfer mode switch body automatically detects the failure and informs the slave servers of the failure so that the master-slave operation is stopped, but when one of the slave servers suffers from a failure, the asynchronous transfer mode switch body automatically detects the failure and informs the master server of the failure so that registration of a slave index number managed by the master server is deleted.
The management information base integrative management method described above is advantageous in that, since simple network management protocol communication with all slave servers is trusted with the master server, the load applied to CPU processing of the asynchronous transfer mode switch body is reduced and the influence upon the processing capacity of the other functions than the simple network management protocol function can be minimized.
The management information base integrative management method is advantageous further in that, since communication between local processors is not used but communication over a virtual connection is used for simple network management protocol communication between the asynchronous transfer mode switch body and the master server and between the master server and any of the slave servers, the communication traffic between local processors can be reduced and the influence upon communication between local processors other, than the simple network management protocol can be minimized.
The management information base integrative management method is advantageous also in that, since communication between the master server and a slave server is performed over a switched vertical connection, consumed resources can be minimized when compared with another case wherein they are normally connected to each other by a permanent vertical connection.
The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements are denoted by like reference symbols.